Electrical connector



JUL 11 1949. L w. J. KoRTH 2,459,032

ELEc'rnIcAL CONNECTOR Fuga opt. 5, 1946 (h. l d'.

F1 ,3 j INVENTOR.

ATTORNEYS Patented Jan. 1l, 1949 ELECTRICAL CONNECTOR William J. Koi-th,Cleveland, Ohio, assignor of one-half to Sam W. Levine, Cleveland, OhioApplication October 3, l1946, Serial No. 700,848

2 Claims. l

This invention relates to a multipart electrical connecting device inwhich the parts may be rotated with respect to each other so that a cordattached to oneof them will not twist or kink. More particularly theinvention relates to such electrical connectors in which connection ismade between a household appliance cord and the receptacle of anappliance or source ofcurrent.

Devices of the type indicated above have been made with the object ofeliminating any twisting or kinking of an electrical cord attached tothem as when one end of the cord is rotated or twisted and the other isnot. Such devices have been made in the form of a multipart connector inwhich two parts mounted on the same central axis could be rotatedrelative to each other and yet maintain the required number ofelectrical connections between the two parts. The prior known devicesfor accomplishing this result have been subject to numerousdisadvantages. Some of these disadvantages arose out of the cost ofmanufacture, as well as the safety and reliability, of such priordevices.

For the uses contemplated, particularly household uses, a low priceditem is essential. On the other hand for the same purposes, andparticularly to secure approval of the underwriting laboratories, thedevices must be safe under all reasonable conditions of use and alsodurable in construction.

The general object of this invention is to provide an improvedelectrical connector of the type indicated in which two parts may rotatefreely with respect to each other while maintaining a plurality ofelectrical connections from the one to the other. Another object of theinvention is to provide such a multipart connector to which electricalconnection may be made in various ways .as by a 'cord or a prongedsocket. Still another object of the invention is to provide such aconnector to one part of which an electric cable may be secured and thatpart rotated freely with respect to another part of the device that iselectrically connected to it. Still another object is to provide aneconomical, safe and dependable type' of multipart connector that may bemade economically for household use and related purposes.

These and other objects will more fully appear from the followingdescription of my invention, the essential features of which aresummarized in the claims, reference being had to the accompanyingfigures in which:

Figure l is an exploded view of one form ofvmy invention;

Figure 2 is a longitudinal section through the axis of rotation of thecentral connector of Figure 1, and;

Figure 3 is a longitudinal section of another form of connector thatembodies my invention.

Referring now to the drawings my invention is shown as directed to anelectrical connector with two parts rotatable relative to each other forlinking the end connectors of one or more cords so that they will notbecome twisted or kinked upon such rotation. The invention is equallyadapted to use with plugs or sockets and similar power outlets whichrequire direct and permanent connection with a cord, as shownparticularly in Figure 3. While those forms of the invention illustratedherein represent preforred embodiments thereof it will be understoodthat modifications may be made without departing from its scope and thatthe invention is limited only by the appended claims.

Essentially the connector in either form comprises a pair of shell-likehousing parts that are freely rotatable with respect to each other abouta common axis. A set of vcooperating terminals are carried by each partand interengage to maintain electrical contact between them and leadsconnected to the parts for every angular position of the parts, thuspermitting an uninterrupted flow of electrical current irrespective ofthe adjusted position of the parts.

As illustrated in Figure 1 acord I to be connected to a source of power,is provided with a p female socket plug 3 at one end that is connectedby an intermediate multipart Connector. made in accord with thisinvention, to a cord 2 leading to any desired power consumption unit andhaving a male plug 4. The multipart intermediate connector is generallyindicated at 5 and,

according to my invention, is adapted to engage.

plugs 3 and 4 and electrically connect cords I and 2 so that they may beturned relative to each otherv without twisting or kinking.

The connector 5, as illustrated in detail in Figure 2, comprises a pairof substantially circular cylindrical shell-like housing parts 6 andland part I define an annular groove I3 in which the flange I0 of shellpart 6 is loosely confined, thereby effectively prohibiting anyappreciable longitudinal movement of parts 6 and I away from each otheralong their common axis of rotation but at the same time enablingrelative rotation between them. An internally threaded portion I I ofthe sleeve 8 engages\with external threads I2 of the part 'I to hold theshells together as shown.

In order to maintain an uninterrupted dow of current across the parts ofthe connector and yet p .rmit rotation between them when desired, theparts are provided Vat opposite ends -with approprate and interconnectedterminals for engaging plugs 3 and 4. These terminals are connected by apair of floating contacts which bridge the rotr able connection andmaintain electrical contact in every angular position.

To maintain contact with a male plug 4 a pair of terminals I4 and I5 ismounted in shell 5 on a cross-piece I6 of Bakelite or similar materialwhich spans the mouth of the part and is secured thereto by screws I1.`The interior of part is provided with two opposed radially extendinglongitudinal ribs I8 which are notched as at I9 in order to mate withthe notched ends of cross-piece I5 and Provide a rm and snug seattherefor. The screws I1 extend upwardly through the cross-piece into theribs as shown. The terminals |4 and |5 are L-shaped metal strips whoseupright portions are positioned to make contact with the prongsof plug 4which extend inwardly through apertures 2| when the connector is in use.The upper ends of each terminal may be bent slightly outwardly as at 22and 23 to facilitate initial contact with the prongs of the plug 4 whenthey are inserted within the connector.

Suitable contacts link the terminals 4 and I5 to prongs mounted inmember 1 to connect with the female plug 3 in order that the ow ofcurrent will be maintained between shell members 6 and 1 and plugs 3 and4 consequent upon their relative rotation. Terminal 24 is preferably aflat annular ring of brass or other conducting metal iixedly seated in acorresponding annular groove 24a in the bottom wall 26 of the interiorof member 1. A prong 21 is formed integrally with the ring and extendsthrough the bottom wall of the connector. Terminal 25 is formed by aflat rectangular plate, preferably of brass, which is mounted in thebottom of a central cylindrical recess 29 in the bottom wall 25. A prong28 is integrally connected to terminal 25. The prongs 21 and 28cooperate to make electrical connection with a mating female plug orsocket that is equipped with prongs similar to those illustrated at 22and 23.

At the time member 1 is molded from Bakelite or other similar insulatingmaterial provision is made for the insertion and retention of terminals24 and 25. The circular groove 24a is formed in the bottom wall ofmember 1 so as to receive the ring in press fit, and a longitudinalgroove receives the prong 21 which extends through the bottom wall 25.The recess 29 is formed in the central portion of the bottom wail sothat terminal 25 will lie in a lower plane as shown in Figure 2 thanterminal 24 and hence be relatively isolated. This aiords to the plug agreater degree of safety if a part becomes broken because it materiallyprevents such broken part from shorting across terminals 24 and 25. Arecess 25a and a longitudinal groove 28a are molded in shell 1 toreceive terminal 25 in press fit and permit insertion of prong 28. Onassembly a Bakelite plug 30 overlies the recess 25a to retain theterminal 25 securely locked in place. If desired as an alternativemethod of assembly, terminals 24 and 25 and prongs 21 and 28 may besecured within member 1 at the time it is molded under heat andpressure. k

In order electrically to connect the two sets of terminals forengagement during 360 of relative movement between members 6 and 1 Iprovide conducting pin members 3| and 32 bridging terminals I4 `and 25and I5 'and 24 respectively. The member 3| comprises a relatively longslender metal pin connected at its upper end to terminal |4 by ailexible connection 33. The pin .passes freely through a hollow rivetl35, which holds terminal I4 to cross-piece I6, and extends into therecess 29 to contact the exposed face of terminal 25 carried by theshell 1. The axis of pin 3| preferably coincides with the central axisof the connector and the pin has a slightly rounded and enlarged head 34to engage terminal 25 against which it is continuously urged by a coilspring 36 surrounding it and interposed between the cross-piece I6 andhead 34.

Pin member 32, in all respects similar to pin 3|, but shorter, isconnected to terminal I5 by a exible lead 31 and extends through andslides freely within the hollow rivet 35 which holds terminal I5 tocross-piece I6. This pin member makes contact with the ring terminal 24by reason of a coil spring 38 which is interposed between thecross-pieceand an enlarged head 39 of the pin.

It is this described arrangement which enables the connector to functionin the desired manner. Assuming that part 6 is rotated with respect topart 1, pins 3| and 32 will be carried along by the crosspiece I5 and,being permanently connected with terminals I4 and I5, will transmitcurrent by maintaining wiping contact with terminals 24 and 25respectively. The pin 3| and terminal 25 rotate with respect to eachother about the axis of rotation of shell members Ii4 and 1 meanwhilecontinuously making electrical connection. At the same time pin 32traces out a circular path over terminal 24 maintaining elecanother orto a ground position with respect to which the connector may be located.In the present construction this is attained by a combination of meansincluding the location of the terminal ring 24 and the terminal 25 indifferent planes transverse to the axis of rotation of the shell members6 and 1. This reduces any likelihood of shorting between the parts suchas might occur if the terminals were positioned with their exposedsurfaces in the same plane transverse to the said axis of rotation.

The safety aiorded by this construction is supplemented by provision ofa sleeve 43 that loosely surrounds the spring 36 and its associated pinmember 3|. The sleeve is somewhat shorter than the normal axial distancebetween the opposed faces of the terminal 25 and the cross member I6. Itis constructed of insulating material to act as an electrical insulatorinterposed between the groups of elements making electrical connectionthrough the pins 3| and 32 respectively. Also, if any parts of the pin3| or the spring 36 should break, they will be retained within thesleeve 40 and thus will be prevented from shorting across to those othercontact elements cooperating with pin 32.

In order to assemble the connector, the contacts 3| and 32, with theassociated sleeve 4|! and springs 36 and 38 are connected to the part 5by inserting the ends of the contacts through ananas the respectivehollow rivets extending through cross-piece I6 and wiring them toterminals I4 and I5 respectively. The cross-piece I6 is then fastened topart 6-by the screws I1. Parts 6 and 'I are positioned adjacent eachother with their open ends abutting and external threaded sleeve 8 isscrewed down until the parts 6 and 1 are brought together. In thisposition contact II bears against the central portion of terminal 25 andcontact 32 rides on the ring 24 due to the force of the coil springs 36and 38 respectively.

My invention is illustrated in another form in Figure 3 that is adaptedto be attached directly and permanently to an electric cord. In thisparticular form the connector or plug does not differ from thatillustrated in Figure 1 in principle but only with respect to part 6 andits associated terminals I4 and I5. In the form of Figure 3 the part 6is replaced by a substantially cylindrical cap 42 having a flange 4Iwhich cooperates With part 'I and sleeve .8 in the same manner aspreviously described for part 6 and flange I0.

A cord 41 is passed through the opening 43 of cap `42 and the separateleads 48 and 49 oi' the cord are attached to the conventional screwterminals 45 and 46 respectively. The terminals 45 and 46 are preferablymounted on internally threaded hollow rivets 5D and 5I respectively,extending through the cross-piece I 6 and each comprises a washer and abolt threaded into the rivets from the bottom side of the cross-piece.Pin contacts 3I and 32 -extend upwardly through hollow rivets asdescribed above with regard to the connector of Figure 2 and areconnected to the terminals by wires 33 and 31 in the same manner.

The form of the invention illustrated in Figure 3 is assembled in thesame manner as described in connection with the form of Figure 2 andoperates in the same way. As the cap 42 and the shell 1 rotate withrespect to each other as permitted by the sleeve 8, electrical connecvtion is continuously maintained between the leads 48 and 49 of the cord41 and the prongs 21 and 28. This is accomplished as heretoforeexplained by the connection made through pins 3| and 32 with theterminals 25 and 24 respectively.

From the foregoing description it will be seen that my present inventionembodies a multipart electrical connector that may take severaldifferent forms and that effectively prevents any twisting or kinking,due to rotation of the parts, of a cable or cables connected to it. Thusa cable or device connected to one part of the multipart connector maybe held stationary while another and electrically connected part of theconnector is rotated to facilitate engagement with either another cordor cable or another elec trical device.

As indicated above various modifications may be made in the presentinvention without departing from the scope thereof and it is to beunderstood that I consider such modifications to form part of thepresent invention, such invention being limited only by the appendedclaims.

I claim:

1. In a device of the character described, two hollow molded dielectricshell members adapted to be mounted with their hollow portions openingtoward each other and detachably joined together for relative rotationabout a common axis, a cross member secured to one of said shellmembers, contacts carried by said cross member on the inner face thereofto make electrical connection with the prongs of a male plug connectingdevice entering into said one hollow shell. two guideways formed in saidcross member, one extending along the axis of rotation of said shellmembers and the other parallel thereto, vpins slidably carried in eachof said guideways,` electrical connections between each of said pins andthrough said contacts to each of said prongs respectively, a shield ofinsulating material enclosing substantially the whole free length of theaxially extending pin, a terminal in one plane of said other shell andin alignment with said axially mounted pin, an annular terminal ringmounted in another plane of said other shell spaced from said firstplane and adapted to encircle said axially mounted pin, coil springsencircling each of said pins and bearing at one end against said crossmember and at the other end against said pins to urge said axiallymounted pin into electrical contact with said terminal and said otherpin into electrical contact with said terminal ring, and electricalconnector prongs integral with said terminal and terminal ringrespectively and passing through said other shell to the exteriorthereof for engagement with a female plug socket.

2. In a device of the character described, two hollow molded dielectricshell members adapted to be mounted with their hollow portions openingtoward each other and detachably joined together for relative rotationabout a common axis, a cross member secured to one of said shellmembers, contacts carried by said cross member on the inner face thereofto make electrical connection with the prongs of a male plug connectingdevice entering into said one hollow shell, two guideways formed in saidcross member, one extending along the axis of rotation of said shellmembers and the other parallel thereto, pins slidably carried in each ofsaid guideways, electrical connections between each of said pins andthrough said contacts to each of said prongs respectively, a relativelydeep cylindrical recess located axially in said other shell and aterminal in the bottom of said recess, and an annular terminal ringmounted in said other shell in a plane above said recess and adapted toencircle said recess and said axially mounted pin, coil springsencircling each of said pins and bearing at one end against said crossmember and at the other end against said pins to urge said axiallymounted pin into electrical contact 'with said terminal and said otherpin into electrical contact with said terminal ring respectively, asleeve of insulating material enclosing substantially the whole freelength of said axially extending pin and associated coil spring andelectrical connector prongs integral with said terminal and terminalring respectively and passing through said other shell to the exteriorthereof for engagement with a female plug socket.

WILLIAM J. KORTH.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Date.

